Blade of the Moon Princess (Gekka Bijin) is a manga written and illustrated by Tatsuya Endo (who would later become best known for Spy X Family), which was serialized in Jump Square from 2010 to 2012 and compiled into five volumes. The story and characters take inspiration from the classic Japanese folktale The Tale of the Bamboo Cutter.
Princess Kaguya is the hotblooded and rebellious young princess of the moon, and the only heir to her mother's throne. She struggles with learning to be an "impressive woman", not helped by her mother's strict and cold attitude and the growing unrest in the empire. When the Ume, a disgraced branch of the royal family, decides to throw a coup during her coming of age ceremony, her mother sends her down to Earth — also known as "The Tainted World" — in order to keep her and the royal blade safe.
Kaguya must learn to become worthy of wielding the blade she now carries. This means she needs to learn to defend herself, protect others, and become a woman that her mother can be proud of — all while dealing with Ume assassins following her to the Earth.
Tropes found in this manga include:
- Abusive Parents: While Fujiya does love Kaguya and want her to succeed, she's also extremely strict and cold towards her, an attitude that only serves to escalate her daughter's rebellious nature. Kaguya, for her part, just wants to make her mother proud while also chafing under the restrictions and responsibilities of princesshood — but instead of getting any comfort or sympathy is instead berated, forced into long and difficult training procedures, and is later locked up after getting into trouble one day.
- Actionized Adaptation: With Princess Kaguya being a bonafide Action Girl, it's safe to say that this is a lot more action-packed than The Tale of the Bamboo Cutter.
- Anti-Hero: Kaguya is stubborn, lazy, hot-tempered and rude to the point where the imperial guard can't stand her. She's also got her heart in the right place, will stand up for people in need, and truly does care about being a proper queen who can protect her home and loved ones.
- Battle Couple: Shishimaro and Suzume are an elderly married couple deeply in love; they're also both highly skilled fighters who, whether separate or together, can hold their own against the Ume branch's assassins and work as a team protecting Kaguya.
- Combat Pragmatist: Kaguya likes to use a few dirty tricks in battle, which other characters consider disgraceful. On one instance, she removes her clothes in order to get away, something that both surprises and angers her mentor Sishimaro. Later, in the fight with Gai, she pulls two dishonorable moves. She first throws pepper in his face to briefly disarm him, and then tricks him by dropping the sword into a snare and delivering a sucker-punch when Gai is watching it be taken by the rope.
- The Cracker: Abiko is a whiz with computers and in just a short time manages to hack into government databases, doing so for the sake of collecting information about suspected treason and his father's own arrest years earlier. He's arrested and exiled to the tainted world for these things, and this is after spending time living with another hacker who sells classified information for money.
- Cut Short: The manga was cancelled after 21 chapters due to low readership.
- The Famine: Kaguya comes across a village that's struggling to grow any crops. Any food they do grow gets taken away by an evil nobleman, and the villagers get harshly punished for not meeting quotas. Tamakichi and his mother barely have enough food to get by, so his mother passes on meals, and Tamakichi protests when she wants to feed Kaguya.
- Foil: Kaguya and Izumiya, as the two royal princesses from both branches of the family, are almost complete opposites. Where Kaguya is emotional, immature, and hot-headed, Izumiya is stable, rational, and calm. Behind her flaws, Kaguya is shown to be an empathetic person who, despite her bad attitude, does do her best to help people when she can. Izumiya, while putting on an act as a pop idol, is ruthless and cruel, and only cares for her own pursuit of power. This is demonstrated in flashbacks to childhood, such as where Kaguya is sobbing during a ceremony because someone at school was mean to her, while Izumiya silently judges her and then shows no sympathy for her cousin's sensitive state.
- Greed: Inbe torments a small village by showing up to demand food on the regular, simply because he can. When they can't give him any, he casually suggests they hand over any valuables they may have. Later, after deciding to no longer steal their food, he plans to sell the women into slavery simply to earn money and go to the capital.
- God Save Us from the Queen!: Hatoya Umenouchi, the empress preceeding Fujiya, was a bloody tyrant who slaughtered citizens and earned the nickname "the pestle empress". She's the one responsible for the Ume branch being cast out of favor and replaced with the Take branch, and frighteningly, Izumiya idolizes her.
- Idol Singer: Izumiya wants to sway the favor of the populace towards her and away from Kaguya and Fujiya. Part of this involves going on tour as an idol singer, masquerading as someone cheerful and sweet while going on tour around the empire.
- I Just Want to Be Normal: A large part of Kaguya's rebelliousness stems from having wanted a normal childhood, like her peers. She lamented the fact that she had to be the queen's daughter, and only wanted to feel like an average kid with average issues.
- Intrepid Reporter: Abiko's father was a heroic journalist who reported on government corruption, winning journalistic awards and being deeply admired by his son. Unfortunately, he was later framed for terrorism by the Ume branch, ruining his reputation and getting exiled from the empire. After learning that he was targeted for digging too close to the ongoing conspiracy, Abiko makes it his goal to be like his father and serve justice through journalism — even warning Kaguya that he'd go after her if she did wrong.
- Jetpack: Mikuni tries to get Kaguya to safety with a jetpack after the battle in the Ume base. They zip off, but soon learn that the jetpack was busted, so they crash in the forest soon after.
- Just Like Robin Hood: Tamakichi's goal is to one day become a famous bandit who can rob the nobles in revenge for their cruel actions toward his village. He later attempts to sneak into Inbe's palace and steal back the village's food, but gets caught.
- Masculine Girl, Feminine Boy: Kaguya is brash, rude, stubborn, and violent; she pairs up with the sensitive, romantic musician Mikuni, who is determined to get her to safety but is often the victim of her bad attitude.
- Modest Royalty: Fujiya is the queen of the Lunar Empire, but she refuses to indulge in anything she doesn't deem a necessity because she believes their money is better suited for other things. She berates a governor for wanting to throw a soiree instead of simply feeding his people, and is shown having yelled at a young Kaguya for wanting something as simple as a a fancy hairpin, just like the girls in her class have.
- Not Quite Flight: Kaguya can be catapulted into the air with the help from the sword, sending herself upward by directing energy into the ground. The others describe this as flying, but she crashes down soon after taking out Gai, who is hovering with technology.
- Power Limiter: The royals have implants to prevent them from using the sword destructively unless ready. Kaguya is convinced that it can only be used for defense until told otherwise. While the trick to remove this limiter is painful — for Kaguya it involves being shot in the stomach — it allows her to finally fight her enemies instead of running and defending.
- Pyromaniac: One of the Ume assassins comes to Earth in full armor and wielding a flamethrower. He tries to burn the heroes alive and even claims to not care about the politics of the fight; he just wants to know what burning princess smells like.
- Royals Who Actually Do Something: Fujiya is very active in her role as the queen, seeing it as her duty to protect her people and even fighting back a deadly illness. Kaguya herself is much lazier and much more rebellious, but she still takes her role as a princess seriously and uses her status to defend a village from Inbe, rather than sit by and let him steal food.
- Secretly Dying: Queen Fujiya puts on a front of being strong and invincible, an ideal queen. Only she and the closest members of her court know that she's very sick, to the point of barely being able to perform her duties. Not even Kaguya knows about this, as Fujiya didn't think she'd be able to handle admitting it to her. When she does find out, she's absolutely horrified, both shocked and angry, and guilty to have caused her mother so much extra stress.
- Sissy Villain: Gai is effeminate, dressed in sexually revealing and stereotypically feminine clothing, and is even mistaken for a woman by Kaguya. He's also looking to kill Kaguya, as well as anyone who gets in the way of doing so. It's played with in that he's still a strong warrior who can hold his own in a fight and simply prefers to present himself this way. He even calls out Kaguya's hypocrisy in the way that she herself doesn't follow traditional gender norms.
- Situational Sword: The sword responds to Kaguya's emotions, and there's a limited amount of energy she's able to draw from it at any given time until she has full control over it.
- Struggling Single Mother: Tamakichi is raised by only his mother, who often sets aside a decent meal so that he can eat properly. Making matters worse, they live in a poor village that's struggling with a famine.
- Wicked Wastefulness: Inbe repeatedly steals from a small and starving village, showing up regularly to demand food payouts. However, we later see him eating a bowl of rice while complaining about the actions of Kaguya, at which point he decides he no longer wants the food — kicking it onto the floor and calling it "shabby". This makes the eavesdropping Tamakichi furious, as he and his mother never have enough to eat and the food came from the people of their village.
- Would Hurt a Child:
- Inbe prepares for a public execution on Tamakichi, a young boy, for the crime of merely breaking into his mansion.
- The Ume branch soldiers are willingly rounding up every local woman and girl in their hunt for Kaguya. When they can't find her, they prepare to kill the lot, including the children. One large and cruel soldier even tries to beat a mother and her daughters for begging for mercy.
